This invention relates to structures that can be used to make connections between tubular medical grafts and a patient""s tubular body conduits. The invention also relates to methods for making and using the structures mentioned above.
Tubular grafts are frequently needed in medical procedures. For example, a coronary bypass procedure may involve the installation of a tubular graft between an aperture that has been formed in the side wall of the aorta and an aperture that has been formed in the side wall of a coronary artery downstream from an occlusion or blockage in that artery. Each end of the graft must be connected to the side wall of either the aorta or the coronary artery. Each such connection must extend annularly around the associated end of the graft conduit and be fluid-tight so that no blood will leak out. One common way to produce such connections is by suturing. It will be appreciated, however, that making such connections by suturing can be extremely difficult, time-consuming, and dependent on the skill of the physician for the quality of the results. There is also increasing interest in less invasive procedures which tend to impose constraints on the physician""s access to the sites at which graft connections must be made and thereby make it more difficult or even impossible to use suturing to make such connections (see, for example, Goldsteen et al. U.S. Pat. No. 5,976,178, Sullivan et al. U.S. Pat. No. 6,120,432, and published PCT patent application WO 98/55027, all of which are hereby incorporated by reference herein in their entireties).
Various types of mechanical connectors have been developed to reduce or eliminate the need for suturing; but improvements are constantly sought for such mechanical connectors with respect to considerations such as ease and speed of use, ease of manufacture, strength and permanence of the resulting connection, etc. A connector, including methods for making and installation thereof, is disclosed in published PCT patent application WO 99/38454, and is incorporated by reference in its entirety herein.
In view of the foregoing, it is an object of this invention to provide improved and simplified graft connectors for connecting two tubular structures without the use of sutures.
It is still another object of this invention to provide improved and simplified methods of making structures that can be used as medical graft connectors.
It is yet another object of this invention to provide improved and simplified methods for installing medical graft connectors.
These and other objects of the invention are accomplished in accordance with the principles of the invention by providing a connector which may be attached to two tubular structures without the use of sutures or other attachment means. The connector is preferably formed by using a highly elastic material such as nickel and titanium alloy (nitinol) metal. A first plurality of fingers is configured to engage an interior surface of the side wall of the existing conduit. A second plurality of fingers is configured to engage an exterior surface of the side wall of the existing conduit. A third plurality of fingers is received in an interior lumen of the graft conduit, and a fourth plurality of fingers is configured to pierce the graft conduit. The connector is radially deformable between a first size and a second size.
In a preferred embodiment, the pluralities of fingers are substantially radially aligned with respect to a longitudinal axis of the connector. The first and second pluralities of fingers may be resiliently deformable towards parallelism with the longitudinal axis of the connector. A substantially xe2x80x9cUxe2x80x9d-shaped configuration may be defined by adjacent ones of the first and second plurality of fingers when viewed from a plane extending radially out from a longitudinal axis of the connector.
To install the graft connector in a patient, a tubular graft conduit is attached to the connector. The first and second pluralities of fingers of the connector may be deflected inwardly toward parallelism with the longitudinal axis. The connector and graft conduit may be inserted in a delivery apparatus, which may maintain the fingers in their substantially axially extending condition. The delivery apparatus may then be inserted through the aperture in the side wall of the patient""s tubular body conduit to which the end of the graft conduit is to be attached. The delivery apparatus is manipulated such that restraint is removed from the fingers of the connector. This permits the fingers to spring out to engage the tissue structure to which the connection is to be made. The delivery may be performed by passing the delivery structure intraluminally within the patient""s tubular body conduit and through the wall of the body conduit to outside the conduit.